In roll briquetting presses of this kind, the individual screw conveyors whose delivery ends are juxtaposed in the space between the rolls, that is, in the space leading to the nip thereof, are arranged alternately at an acute angle to the vertical. In order to achieve a uniform coverage of the rolls during briquetting and compacting of feed materials in a roll press of this kind, it has already been proposed to regulate the drive of the screw conveyors so that they are driven with constant angular momentum. In spite of this, regularity of covering the press roll is not entirely satisfactory if the feed material is difficult to handle, for example, burnt lime.
An object of the invention is to provide means by which in a roll briquetting process of the above kind a uniform coverage of the rolls with the feed material is rendered possible even for feed materials that are difficult to handle, and thereby to ensure uniform quality of the briquettes across the whole width of the press rolls.
This problem is solved according to the present invention by providing, below the ends of the screw conveyors which project into the space between the rolls, adjustable tongue-shaped plates.
These tongue-shaped plates are hereby suitably located below the ends of the screw conveyors tangentially to the roll circumference. The tongue-shaped plates are preferably inclined at an angle of less than 45.degree.to the vertical.
There is preferably provided for each screw conveyor at least one separate tongue-shaped plate, while in practice one tongue-shaped plate for each screw conveyor has been found sufficient in most cases. In this case the breadth of the tongue-shaped plate corresponds essentially to the diameter of the housing of the associated screw conveyor.
There is suitably provided, below the lower end of the screw conveyor, above and parallel to the tongue-shaped plate, a fixed plate extending across the width of the filling well. The length of the fixed plate may be greater than half the distance between the lower end of the screw conveyor housing and the opposite roll, measured in the plane of the tongue-shaped plate. The length should, however, be less than three quarters of this distance.